Facebook is holding an April 4 event at its Menlo Park campus, promising to show off the company’s “New Home on Android.”

TechCrunch’s Josh Constine reports sources as saying “it will be a modified version of the Android operating system with deep native Facebook functionality on the homescreen that may live on an HTC handset.”

This wouldn’t be the first phone to get deeper-than-normal Facebook integration. It wouldn’t even be the first HTC phone to do so — the HTC Status had its own Facebook hardware button. Two handsets from the U.K.’s Inq were also positioned as Facebook phones.

As Constine points out, Facebook may not be in the right place to work out the hardware details of a company-branded handset: “This announcement might not be a Facebook Phone, but rather a Facebook phone — one where everything the user sees is social by design, even if the handset’s innards are made by someone else.”

So potentially another Facebook phone, but perhaps a bit Facebook-ier than previous Facebook phones. And probably not a capital-P Facebook Phone. We’ll know more for sure on Thursday.